1. Field of the Invention
This invention relates to lever lid containers and more particularly but not exclusively to a lever ring attachable to the container body and adapted to receive a plug lid which may be progressively levered out of the ring to open the container.
2. Description of the Prior Art
Lever lid tins have been used by the paint trade for many years. They are usually made of tinplate and comprise a body having a bottom end; a cylindrical side wall having a side seam which may be a folded and soldered side seam or a lap welded side seam; and a lever ring which is attached to the top of the side wall by a double seam. The plug portion of a lever lid is frictionally held in the ring.
The water based paints now widely used have subjected the tinplate lever ring to a much greater risk of corrosion especially at the worked surfaces and cut edges of the ring disposed inside the container headspace. It is therefore desirable to provide a lever ring which can survive the corrosive environment in the container.
Conventional tinplate lever rings comprise an annular cover hook for double seaming, a chuck wall depending from the interior of the cover hook, a folded portion supporting a flared portion extending from the chuck wall radially and axially back concentrically within the chuck wall to a second fold portion from which depends a cylindrical lid receiving portion. The flared portion thus holds any lid fitted up at a level substantially flush with the top of the container body giving a neat appearance and access for insertion of a lever used to remove the lid from the ring.
However this arrangement of the flared portion presents a possibility that the axially applied forces used to push the lid into the ring will crush the flared portion, so closing the aperture defined by the lid receiving portion and making it more difficult to fit the lid. If the closed container is subjected to abuse, of the kind which is tested by the usual drop tests, the hydraulic pressure within the container acts on the lid which in turn passes the hydraulic force on to the flared portion which may yield beyond its intended shock absorbing flexure to permit the lid to be forced out of the ring.